Effect of high-dose delivery on the attachment of meningiomas in Gamma Knife surgery: a retrospective study.

BACKGROUND: Meningiomas have vascular supply from the tumor attachment on the dura mater. Gamma Knife radiosurgery (GKS) is known to have a vascular obliterating effect. This study aims to determine the benefits of high-dose irradiation to the tumor attachment compared to conventional dose planning in the long-term control of tumor growth with GKS. METHODS: Two different dose plannings were retrospectively compared in 75 patients with meningioma treated with GKS as a primary treatment. Forty-three patients were irradiated over 20 Gy to the tumor attachment. The remaining 32 patients were treated with conventional-dose planning. Tumor growth control, reduction of enhancement on the gadolinium-enhanced magnetic resonance imaging (MRI), and neurological status were retrospectively assessed. RESULTS: The maximum dose on the tumor attachment was significantly higher in the high-dose group (23 Gy) than in the conventional group (16 Gy). The tumor margin was irradiated with the median of the 50% isodose line in both groups. The prescription doses resulted in 14 Gy and 12 Gy, respectively. The tumor control rate achieved 91% in both groups during the median follow-up period of 54 months. A decrease of enhancement on follow-up MRI was noted in one patient in each group. Kaplan-Meier analysis revealed no statistical difference in the progression-free survival between the two groups. The number of patients with improved neurological status showed no statistical difference. CONCLUSIONS: No obvious benefit of high-dose irradiation to the tumor attachment and margin was found in tumor control and neurological status in the long term.

Preoperative Evaluation of the Effects of Sigmoid Sinus Ligation with both Endovascular and Open-Field Occlusion Tests before Removal of Petroclival Tumors.

Background Surgery for petroclival tumors is very challenging for neurosurgeons because the position of the tumor in relation to the brainstem, cranial nerves, and posterior fossa vessels greatly restricts the surgical field. Some papers have described using sigmoid sinus ligation to open the surgical field; however, pre- and intraoperative evaluations of the safety of ligation have been limited, despite the risk of complications from venous insufficiency. Here, we describe our method of preoperatively evaluating the potential safety of a retrolabyrinthine transsigmoid approach with nondominant ipsilateral sigmoid sinus ligation (RLTSwSSL). Methods A retrospective review was conducted on petroclival tumors treated over a 5-year period with RLTSwSSL after evaluation with both an endovascular balloon occlusion test (BOT) and an open-field sinus clipping occlusion test (COT). Changes in pressure of < 10 mm Hg and the absence of neurodegeneration during the tests indicated that it would be safe to proceed with permanent ligation. Results Four patients with large petroclival tumors underwent surgery via RLTSwSSL after detailed preoperative evaluations with both BOT and COT. All patients had uneventful courses of recovery without developing any complications derived from venous insufficiency. Conclusion In our case series, we have described a protocol for using both BOT and COT to evaluate the likely outcomes after sigmoid sinus ligation and thereby to improve safety. Further studies are needed to establish definite criteria for both occlusion tests that will ensure good outcomes.

Bilateral Chronic Subdural Hematoma in the Posterior Fossa Treated with a Burr Hole Irrigation: A Case Report and Review of the Literature.

Chronic subdural hematoma (CSH) in the posterior fossa is extremely rare. The surgical strategy is still controversial. We report a case of bilateral CSH in the posterior fossa successfully treated with a single-burr hole surgery. A 74-year-old man under anticoagulation and antiplatelet therapy developed headache and nausea during observation for an asymptomatic supratentorial CSH. Radiological examinations revealed appearance of bilateral CSH in the posterior fossa associated with hydrocephalus. Upon rapid deterioration of the patient's consciousness, an urgent treatment was required. A burr hole was made near the transverse-sigmoid junction on the left side to access the hematoma. No ventricular drainage was placed as his consciousness improved during the decompression of the hematoma. Postoperative computed tomography showed that bilateral CSH and hydrocephalus had been successfully treated. In bilateral CSH in the posterior fossa, there may be a connection between each side. CSH in the posterior fossa, when urgent, can be treated under local anesthesia with a unilateral burr hole irrigation.

Intradural Lipoma at the Craniocervical Junction Presenting with Progressing Hemiparesis: A Case Report.

Intradural spinal lipomas are rare in an adult population. They are mostly asymptomatic and usually associated with spinal dysraphism in a pediatric population. We report a rare case of spinal lipoma without dysraphism and with progressing hemiparesis. A 60-year-old woman had incidental lipoma at the craniocervical junction observed for more than 5 years. Recently, she developed right-sided hemiparesis and sensory disturbance. Radiological studies revealed a large lipoma compressing the dorsal medulla and C1-C2 spinal cord. Standard midline suboccipital craniotomy and C1 laminectomy were performed, and the lipoma was removed subtotally. The lipoma showed severe adhesion to the dorsal medulla and C1 spinal cord; therefore, the excision was limited as internal debulking. Her neurological deficit subsided within 6 months after the decompressive surgery. Considering the benign nature of lipoma, internal decompression is a reasonable management for this lesion.

Correlation of Appearance of MRI Perinidal T2 Hyperintensity Signal and Eventual Nidus Obliteration Following Photon Radiosurgery of Brain AVMs: Combined Results of LINAC and Gamma Knife Centers.

BACKGROUND: A wide variety of radiologic changes occur within and adjacent to the nidus of arteriovenous malformations (AVMs) after stereotactic radiosurgery (SRS). Our objective was to study the magnetic resonance imaging(MRI)-defined changes following photon radiosurgery of AVMs and specifically to correlate the appearance of a perinidal T2 hyperintensity signal with the eventual angiographic obliteration of an AVM nidus in response to SRS treatment. MATERIAL AND METHODS: This retrospective study was conducted on 62 patients with brain AVMs who received photon SRS treatments between 2004 and 2017, using either a technique based on a linear accelerator at the Alexandria LINAC Radiosurgery Center in Egypt (21 patients/AVMs) or a technique based on a gamma unit at the Koto Memorial Gamma Knife Center in Japan (41 patients/AVMs). All patients included in the study had serial clinical and radiologic follow-ups for ≥ 2 years after SRS treatments. RESULTS: In the combined study series of 62 patients/AVMs treated with photon SRS, the follow-up MRIs revealed that 50 AVMs (80.6%) showed nonvisualized nidus and 12 AVMs (19.4%) showed decreased nidus size. Radiation-induced changes, defined as appearance of perinidal T2 hyperintensities in post-SRS MRIs, occurred in 34 patients (54.8%). Of the 35 patients with available follow-up angiographic studies, 30 AVMs (85.7%) demonstrated complete nidus obliteration at a mean of 36 months (range: 8-66 months) after SRS. Of the 30 AVMs with both MRI evidence of a nonvisualized nidus and angiographic verification of complete nidus obliteration, 20 AVMs (66.7%) were associated with prior MRI evidence of the appearance of a perinidal T2 hyperintensity signal at an average of 12 months (range: 6-45 months) after SRS. Of the five AVMs with both MRI evidence of decreased nidus size and angiographic verification of partial nidus obliteration, four AVMs (80%) showed perinidal T2 hyperintensity signal on post-SRS follow-up MRIs. Lower Spetzler-Martin grade (p = 0.013), smaller AVM volume (p = 0.017), and appearance of post-SRS perinidal T2 hyperintensity signal (p = 0.007) were the statistically significant independent predictors of AVM obliteration. The appearance of perinidal T2 hyperintensity signal in the post-SRS MRIs had a sensitivity of 66.7%, a specificity of 20%, and an overall accuracy of 60% in predicting the eventual obliteration of the AVM nidus. CONCLUSIONS: The present study may help improve our current understanding of the mechanisms behind the radiation-induced tissue changes following AVM SRS. Because the SRS-induced hemodynamic changes within the AVM nidus initiate the cascade of the subsequent formation of perinidal vasogenic brain edema, the appearance of perinidal high T2 signal in the follow-up MRIs after SRS would be a valuable indicator of the AVM response to SRS. The development of perinidal hyperintensity was the strongest predictive factor of AVM obliteration (p = 0.007), with relatively high sensitivity (66.7%) and accuracy (60%) and fairly low specificity (20%), as a prognostic sign of eventual complete angiographic obliteration of the AVM nidus following SRS.

Intraventricular Epithelioid Glioblastoma: A Case Report.

BACKGROUND: Epithelioid glioblastoma, a high-grade, diffuse astrocytic tumor variant, comprises closely packed epithelioid cells and rhabdoid cells. This rare tumor usually develops in the cerebral cortex and diencephalon; however, in the case reported here, it was located intraventricularly. CASE DESCRIPTION: A 47-year-old woman was referred to our hospital with a right intraventricular mass that had rapidly increased in size. On discovery of the tumor 3 years earlier at the referring hospital, the mass was small, calcified, and attached to the periventricular parenchyma. Over the next 2 years, the mass grew slowly, as observed on periodic magnetic resonance imaging scans. Forty days before the referral, the patient experienced headache and nausea, and marked growth and intratumoral hemorrhage were visible on a computed tomography scan of the head. The tumor was partially removed via a superior parietal lobule corticotomy. Histopathological examination confirmed an isocitrate dehydrogenase-wild-type epithelioid glioblastoma with a BRAF V600E mutation, but the original slow-growing lesion was no longer detected. Consequently, we assume that in this case, a low-grade glioma transformed into an aggressively malignant epithelioid glioblastoma. CONCLUSIONS: We present the first case of an intraventricular epithelioid glioblastoma that might have arisen from a low-grade glioma with calcification. We recommend including this tumor variant in the differential diagnosis of lateral ventricle tumors.

Single-stage total resection of giant dumbbell-shaped hypoglossal schwannoma: a case report.

Extensive large dumbbell-shaped hypoglossal schwannoma is extremely rare, and total resection is nearly impossible. We present a case of a 61-year-old male with a giant-size hypoglossal schwannoma with moderate tongue atrophy. The tumor extended from the enlarged hypoglossal canal to the brainstem intradurally and the high cervical region extradurally. Through the extreme lateral infrajugular transcondylar (ELITE) skull base approach, the tumor was totally removed in a single-stage operation. Single-stage total resection is feasible by an experienced skull base team utilizing transcondylar skull base techniques and high cervical dissection.

Trigeminal neurofibroma in the infratemporal fossa arising from the inferior alveolar nerve: A case report.

Solitary neurofibromas arising from cranial nerves are rare, and those arising from the peripheral divisions of the trigeminal nerve are even rarer. Although infratemporal fossa (ITF) masses are challenging to remove, certain approaches are considered feasible for this region. The present study reports a rare case of an ITF neurofibroma arising from the inferior alveolar nerve. The 27-year-old male patient presented with numbness of the right jaw. A radiological examination revealed a large mass occupying the ITF, from the mandible to the foramen ovale, originating from the inferior alveolar nerve in the mandible. The tumor was successfully excised via a transtemporal approach followed by a transoral-retromolar approach. A histological examination confirmed the diagnosis of neurofibroma. The present case demonstrates that a combination of the transtemporal and transoral-retromolar approaches may provide wide access to the ITF region.

Long-term outcomes of microvascular decompression and Gamma Knife surgery for trigeminal neuralgia: a retrospective comparison study.

BACKGROUND: There is still no clear guideline for surgical treatment for patients with medically refractory trigeminal neuralgia (TN). When it comes to which surgical treatment to choose, microvascular decompression (MVD) or Gamma Knife surgery (GKS), we should know the long-term outcome of each treatment. METHODS: We analyzed 179 patients undergoing MVD and 52 patients undergoing GKS followed for 1 year or longer. We evaluated the patient's neurological status including pain relief, complications and recurrence. Results were assessed with Barrow Neurological Institute (BNI) pain intensity and facial numbness scores. Overall outcomes were compared between the two groups based on pain relief and complications. RESULTS: BNI pain intensity and facial numbness scores at the final visit were significantly lower in the MVD group than in the GKS group (P < 0.001, P = 0.04, respectively). Overall outcomes were superior following MVD than following GKS (P < 0.001). Following whichever treatment, there were initially high rates of pain-free status "without medication": 96.6% in the MVD group and 96.2% in the GKS group. However, 6.1% in the MVD group and 51.9% in the GKS group fell into a "with medication" state within median periods of 1.83 and 3.92 years, respectively (P < 0.001). Kaplan-Meier analysis revealed that pain recurred more often and later in the GKS group than in the MVD group (P < 0.001). CONCLUSIONS: Considering the long-term outcomes, MVD should be chosen as the initial surgical treatment for patients with medically refractory TN.

Nervus Intermedius Neuralgia Treated with Microvascular Decompression: A Case Report and Review of the Literature.

Nervus intermedius neuralgia is one of the craniofacial neuralgias, which is extremely rare compared with trigeminal or glossopharyngeal neuralgia. Despite its unique symptom, the aetiology remains unclear. We present a case of a surgically treated 36-year-old woman who suffered from paroxysmal stabbing deep-ear pain for over 10 years. Preoperative magnetic resonance imaging demonstrated a vascular loop compressing the root entry zone of the vestibulocochlear nerve between the seventh and eighth cranial nerves, suggesting nervus intermedius neuralgia as a cause of her pain. Surgical exploration revealed that the nervus intermedius was displaced upward by the anterior inferior cerebellar artery. Transposition of the artery from the brainstem relieved the patient's neurological symptom immediately after the surgery, supporting the hypothesis that nervus intermedius neuralgia could be caused by neurovascular compression.

Diagnosis and management for trigeminal neuralgia caused solely by venous compression.

BACKGROUND: Trigeminal neuralgia (TN) caused solely by venous compression is uncommon. An appropriate vein management protocol for microvascular decompression (MVD) has not been established. We evaluated the management of veins for TN solely due to venous involvement. METHOD: We analyzed 31 patients with TN in whom only veins were manipulated during MVD. The culprit veins smaller in diameter than the vein of the cerebellopontine fissure (VCPF) were coagulated and divided in 20 patients (divided group), while transposition was performed for larger veins in the remaining 11 patients (non-divided group). Postoperative outcomes were assessed by Barrow Neurological Institute (BNI) pain intensity score and BNI facial numbness score. RESULTS: Preoperative contrast-enhanced T1 spoiled gradient recalled (SPGR) imaging exhibited higher detection rates for veins (93.5%) than non-contrast fast imaging employing a steady-state acquisition image (74.2%). The transverse pontine vein (TPV) was the most frequently involved vessel. All the divided veins were small TPVs except one. The non-divided group included seven cases of large TPVs and four involving the main trunk of the superior petrosal vein or its large tributaries. The median follow-up duration was 33 months. Pain relief was achieved immediately after the surgery in 28 (90.3%) and within a month in the remaining 3 (9.7%) patients. Numbness was present in seven (22.6%) patients at the final follow-up. Recurrence was observed in only two (10.0%) patients in the divided group compared with four (36.4%) patients in the non-divided group. Comparison at the final follow-up revealed that the divided group had superior outcome compared to the non-divided group. CONCLUSIONS: Contrast-enhanced T1 SPGR imaging is crucial to detect small veins in the preoperative diagnosis. Division of the culprit veins is recommended if the diameter is smaller than the VCPF as it provides a better outcome and lower recurrence rate than transposition.

Trigeminal Neuralgia Due to Red Vein Draining a Supratentorial Arteriovenous Malformation: Case Report.

Trigeminal neuralgia (TGN) is rarely caused by arteriovenous malformation (AVM). The AVMs causing TGN are reported mostly in the ipsilateral posterior fossa. The culprit vessels are dilated feeding artery or nidus itself. We present a rare case of TGN caused by dilated draining veins from a supratentorial AVM. The patient suffered from TGN with an incidentally found large AVM, which had been left untreated. The neuralgia was successfully relieved by microvascular decompression. Dilated red veins compressed the nerve at the root entry zone and distant cisternal portion of the nerve. Technically, transposition is not practical for fragile, dilated red veins with high pressure. Interposition is safer method in this case.

Treatment Results of Gamma Knife Radiosurgery for Central Neurocytoma: Report of a Japanese Multi-Institutional Cooperative Study.

OBJECTIVE: Central neurocytoma (CN) is a rare benign neuronal tumor, and a limited number of reports have described the usefulness of radiosurgery for a relatively large group of patients. We evaluated the effectiveness and outcomes of Gamma Knife radiosurgery (GKS) for CN in a Japanese multi-institutional study. METHODS: We performed retrospective analysis of 36 patients with CN who were treated with GKS in 12 institutes in Japan. All patients underwent surgery before GKS. The median tumor volume at GKS was 4.9 mL (range, 0.07-23.4 mL), and the median radiation dose prescribed to the tumor margin was 15 Gy (range, 10-20 Gy). The median follow-up period was 54.5 months (range, 3-180 months). RESULTS: The local tumor progression-free survival rates at 5 and 10 years were 94% and 86%, respectively. Three patients developed distant dissemination 16-90 months later. Overall progression-free survival was unrelated to the prescribed dose (<15 Gy vs. ≥15 Gy, P = 0.62), tumor size (<6 mL vs. ≥6 mL, P = 0.46), gender (P = 0.36), age (<30 vs. ≥30 years, P = 0.37), target of GKS (residual vs. recurrence, P = 0.90), and type of enhancement (homogeneous vs. inhomogeneous, P = 0.19). Two permanent complications occurred with 1 intratumoral hemorrhage and 1 radiation injury. CONCLUSIONS: GKS is effective for CN because of its high rate of long-term local tumor control. GKS may have a potential role as a primary treatment for asymptomatic, relatively small tumors in the absence of hydrocephalus without surgical resection.

Trochlear Nerve Schwannoma Treated with Gamma Knife after Excision: A Case Report and Review of the Literature.

Trochlear nerve schwannomas are extremely rare. We present a surgically excised case of trochlear nerve schwannoma followed by Gamma Knife (ELEKTA, Stockholm, Sweden) after histologic confirmation. A 52-year-old man presented with diplopia, gait disturbance, and sensory disturbance. Magnetic resonance imaging demonstrated a large cystic mass at ambient cistern on the right side. Subtotal excision followed by Gamma Knife surgery was undertaken. His neurologic symptoms disappeared with radiologic reduction in size at 15-month follow-up. Because Gamma Knife can manage trochlear nerve schwannomas well, surgical excision should be reserved for large ones and limited to subcapsular or subtotal removal with the expectation of possible recovery of neurologic dysfunction.

Trigeminal Neuralgia due to an Isolated Cerebral Varix: Case Report.

Intracranial isolated varix is a very rare entity. Although it is usually asymptomatic, there are reports on symptomatic cases with hemorrhage or mass effect that mostly relate to arteriovenous fistulas or arteriovenous malformations. We present an extremely rare case of trigeminal neuralgia caused by an isolated varix. A 55-year-old woman had been experiencing right trigeminal neuralgia for 3 years. Computed tomography and magnetic resonance imaging revealed an enhanced mass lesion on the root entry zone of the right trigeminal nerve. Angiograms confirmed the mass was a varix arising on the vein connecting the basal vein of Rosenthal and the superior petrosal vein. Preoperative three-dimensional (3D) imaging clearly depicted the anatomical relation of the varix, adjacent vessels, and trigeminal nerve, which helped plan operative procedures. The varix with its parent vein was successfully transposed from the nerve without sacrificing any veins. Her pain disappeared immediately after the surgery and did not recur during a 30-month follow-up period. The 3D image contributed to making an accurate and safer operative plan especially for this rare case.

Ocular neuromyotonia treated by microvascular decompression: usefulness of preoperative 3D imaging: case report.

Ocular neuromyotonia is a rare ocular motility disorder characterized by involuntary contraction of extraocular muscles resulting in paroxysmal diplopia. Although ocular neuromyotonia is reported as a rare complication after radiation therapy, there are a few cases of ocular neuromyotonia in the absence of irradiation. In the reported cases the possibility of vascular compression has been suggested on radiological imaging. The authors report a case of ocular neuromyotonia treated by microvascular decompression of the third cranial nerve, supporting the hypothesis that neurovascular compression may play a role in its pathogenesis. The usefulness of preoperative 3D imaging for microvascular decompression is also discussed.

[A case of patient with malignant lymphoma who received home chemotherapy and achieved a good remission].

There have been an increasing number of aged patients with malignancies. But, there are some patients who can not receive anti-cancer therapy due to poor activities of daily living and/or aging, etc. In Japan, medical practice at cancer patients' home has been expected for best supportive care, and most physicians believe that home chemotherapy is difficult because cancer patients frequently develop complications. We herein report a case of an 89-year-old female affected by malignant lymphoma who received a home chemotherapy and achieved a good remission. The clinical course of the present case suggested that with careful preparations, home chemotherapy might be feasible and one of therapeutic options for cancer patients.

Granule cell dispersion develops without neurogenesis and does not fully depend on astroglial cell generation in a mouse model of temporal lobe epilepsy.

PURPOSE: Granule cell dispersion (GCD) appears as a characteristic morphological feature of the mesial temporal lobe epilepsy (MTLE). It has been suggested that this phenomenon could be due to an increased neurogenesis in the dentate gyrus. However, this hypothesis is still debated and recent clinical and experimental studies have shown that neurogenesis is rather decreased in MTLE. To further determine the role of neural and astroglial cell generation in GCD we examined the consequences of aging and irradiation, which are known to reduce progenitor cells, in a mouse model of MTLE induced by intrahippocampal kainate (KA) injection. METHODS: We injected KA in hippocampus of three different types of mice; (1) young adult, (2) aged, and (3) irradiated mice. Newly generated cells were labeled by Bromodeoxyuridine (BrdU) and were characterized by immunohistochemistry. The extent of GCD was compared among the three animal groups. RESULTS: In young adult mice, BrdU-labeled neurons as well as doublecortin- and NeuroD-positive cells decreased progressively after KA injection whereas BrdU-labeled astrocytes and microglias increased. In aged and irradiated mice, where basal neurogenesis was already strongly reduced, GCD developed after KA injection to the same extent as in young adult mice. However, augmentation of the BrdU-labeled astrocytes after KA was less than 40% in irradiated mice in comparison to young and aged mice. CONCLUSIONS: Our data show that GCD occurs without neurogenesis. Furthermore GCD developed regardless of the degree of astroglial cell proliferation, suggesting that neural stem cell generation is not crucial for GCD.

Intracranial solitary juvenile xanthogranuloma successfully treated with stereotactic radiosurgery.

Juvenile xanthogranuloma (JXG) is a non-Langerhans cell histiocytosis, which primarily affects the skin in young children. Although intracranial involvement is rare, it differs from other systemic JXG because its responsiveness to non-surgical treatment is poor. We present the case of a 2-year-old boy with left abducens nerve palsy. Imaging studies revealed a mass in the left Meckel's cave. Systemic examination showed no other abnormalities including his skin. After partial removal, JXG was diagnosed based on immunohistochemical evaluation. He underwent a stereotactic radiosurgery. Then, the mass decreased, and his abducens nerve palsy improved. This is the seventh case with isolated intracranial JXG, and the first case to be treated with radiosurgery. We consider that stereotactic radiosurgery is an excellent choice for treatment of intracranial JXG.